package com.mq.rabbitmqtrac.util;

import lombok.extern.log4j.Log4j2;
import org.apache.commons.lang3.Validate;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;

/**
 * Spring ApplicationContext工具类
 * 
 */
@Log4j2
@Component
public class SpringApplicationContextUtils implements ApplicationContextAware {

	private static ApplicationContext applicationContext = null;

	/**
	 * 取得存储在静态变量中的ApplicationContext.
	 */
	public static ApplicationContext getApplicationContext() {
		assertContextInjected();
		return applicationContext;
	}

	/**
	 * 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型.
	 */
	@SuppressWarnings("unchecked")
	public static <T> T getBean(String name) {
		assertContextInjected();
		return (T) applicationContext.getBean(name);
	}

	/**
	 * 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型.
	 */
	public static <T> T getBean(Class<T> requiredType) {
		assertContextInjected();
		return applicationContext.getBean(requiredType);
	}

	/**
	 * 清除SpringContextHolder中的ApplicationContext为Null.
	 */
	public static void clearHolder() {
		if (log.isDebugEnabled()) {
			log.debug("清除SpringContextHolder中的ApplicationContext:" + applicationContext);
		}
		applicationContext = null;
	}

	/**
	 * 实现ApplicationContextAware接口, 注入Context到静态变量中.
	 */
	@Override
	public void setApplicationContext(ApplicationContext applicationContext) {
		SpringApplicationContextUtils.applicationContext = applicationContext;
	}

	/**
	 * 检查Spring上下文不为空.
	 */
	private static void assertContextInjected() {
		Validate.validState(applicationContext != null, "不能获取到spring上下文");
	}
}